Mao Yuqi, Pan Leilei, Li Wenping, Xiao Shuifeng, Qi Ruirui, Zhao Long, Wang Junqin, Cai Yiling
Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University, Shanghai, China.
Front Integr Neurosci. 2022 Jul 28;16:941947. doi: 10.3389/fnint.2022.941947. eCollection 2022.
Motion sickness (MS) is caused by mismatch between conflicted motion perception produced by motion challenges and expected "internal model" of integrated motion sensory pattern formed under normal condition in the brain. Stroboscopic light could reduce MS nausea symptom via increasing fixation ability for gaze stabilization to reduce visuo-vestibular confliction triggered by distorted vision during locomotion. This study tried to clarify whether MS induced by passive motion could be alleviated by stroboscopic light with emitting rate and intensity synchronized to acceleration-deceleration phase of motion. We observed synchronized and unsynchronized stroboscopic light (SSL: 6 cycle/min; uSSL: 2, 4, and 8 cycle/min) on MS-related gastrointestinal symptoms (conditioned gaping and defecation responses), motor disorders (hypoactivity and balance disturbance), and central Fos protein expression in rats receiving Ferris wheel-like rotation (6 cycle/min). The effects of color temperature and peak light intensity were also examined. We found that SSL (6 cycle/min) significantly reduced rotation-induced conditioned gaping and defecation responses and alleviated rotation-induced decline in spontaneous locomotion activity and disruption in balance beam performance. The efficacy of SSL against MS behavioral responses was affected by peak light intensity but not color temperature. The uSSL (4 and 8 cycle/min) only released defecation but less efficiently than SSL, while uSSL (2 cycle/min) showed no beneficial effect in MS animals. SSL but not uSSL inhibited Fos protein expression in the caudal vestibular nucleus, the nucleus of solitary tract, the parabrachial nucleus, the central nucleus of amygdala, and the paraventricular nucleus of hypothalamus, while uSSL (4 and 8 cycle/min) only decreased Fos expression in the paraventricular nucleus of hypothalamus. These results suggested that stroboscopic light synchronized to motion pattern might alleviate MS gastrointestinal symptoms and motor disorders and inhibit vestibular-autonomic pathways. Our study supports the utilization of motion-synchronous stroboscopic light as a potential countermeasure against MS under abnormal motion condition in future.
晕动病（MS）是由运动挑战产生的冲突性运动感知与大脑在正常情况下形成的整合运动感觉模式的预期“内部模型”之间的不匹配所引起的。频闪灯光可以通过提高注视稳定的固定能力来减少MS恶心症状，从而减少运动过程中因视觉扭曲引发的视觉-前庭冲突。本研究试图阐明，与运动的加速-减速阶段同步发射速率和强度的频闪灯光是否可以缓解被动运动诱发的MS。我们观察了与MS相关的胃肠道症状（条件性张口和排便反应）、运动障碍（活动减退和平衡障碍）以及接受摩天轮样旋转（6次/分钟）的大鼠中枢Fos蛋白表达情况，包括同步和不同步的频闪灯光（SSL：6次/分钟；uSSL：2、4和8次/分钟）。还研究了色温及峰值光强度的影响。我们发现，SSL（6次/分钟）显著降低了旋转诱发的条件性张口和排便反应，并减轻了旋转诱发的自发运动活动下降和平衡木表现的破坏。SSL对MS行为反应的疗效受峰值光强度影响，但不受色温影响。uSSL（4和8次/分钟）仅能引发排便，但效率低于SSL，而uSSL（2次/分钟）对MS动物没有有益作用。SSL而非uSSL抑制了尾侧前庭核、孤束核、臂旁核、杏仁体中央核和下丘脑室旁核中的Fos蛋白表达，而uSSL（4和8次/分钟）仅降低了下丘脑室旁核中的Fos表达。这些结果表明，与运动模式同步的频闪灯光可能缓解MS胃肠道症状和运动障碍，并抑制前庭-自主神经通路。我们的研究支持在未来将运动同步频闪灯光作为异常运动条件下对抗MS的潜在对策加以应用。
